Field of the Invention
This invention relates generally to large industrial valves for controlling the flow of fluids therethrough. More particularly, this invention pertains to butterfly valves having a metal spring ring valve seat that resiliently deforms radially under hoop stress when seated to thereby create a tight seal when the valve is closed.
General Background
Butterfly valves are used in various industries for controlling the flow of fluids. Butterfly valves are often used in situations wherein the flow through the valve must be throttled. An advantage of using a butterfly valve over other types of throttling valves is that the torque across the butterfly disk of such valves resulting from fluid pressure is generally balanced, thereby making such valves ideal for controlling high pressure fluids (e.g., water flow from damns).
Large butterfly valves typically have replaceable valve seats (one mounted to the housing and the other to the butterfly disk). The valve seat may be metal or polymeric. In some valves, at least one of the seats may be movable with respect to the disk or housing to which it is secured to ensure complete sealing when closed.
The present invention pertains to a metal butterfly valve seat that can articulate, but in a unique manner.